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Showing papers on "Fishing published in 2010"


Journal ArticleDOI
TL;DR: In this article, the authors show that climate change may lead to large-scale redistribution of global catch potential, with an average of 30-70% increase in high-latitude regions and a drop of up to 40% in the tropics.
Abstract: Previous projection of climate change impacts on global food supply focuses solely on production from terrestrial biomes, ignoring the large contribution of animal protein from marine capture fisheries. Here, we project changes in global catch potential for 1066 species of exploited marine fish and invertebrates from 2005 to 2055 under climate change scenarios. We show that climate change may lead to large-scale redistribution of global catch potential, with an average of 30-70% increase in high-latitude regions and a drop of up to 40% in the tropics. Moreover, maximum catch potential declines considerably in the southward margins of semienclosed seas while it increases in poleward tips of continental shelf margins. Such changes are most apparent in the Pacific Ocean. Among the 20 most important fishing Exclusive Economic Zone (EEZ) regions in terms of their total landings, EEZ regions with the highest increase in catch potential by 2055 include Norway, Greenland, the United States (Alaska) and Russia (Asia). On the contrary, EEZ regions with the biggest loss in maximum catch potential include Indonesia, the United States (excluding Alaska and Hawaii), Chile and China. Many highly impacted regions, particularly those in the tropics, are socioeconomically vulnerable to these changes. Thus, our results indicate the need to develop adaptation policy that could minimize climate change impacts through fisheries. The study also provides information that may be useful to evaluate fisheries management options under climate change.

892 citations


Journal ArticleDOI
TL;DR: It is shown that phytoplanktonic primary production, estimated from an ocean-colour satellite (SeaWiFS), is related to global fisheries catches at the scale of Large Marine Ecosystems, while accounting for temperature and ecological factors such as ecosystem size and type.
Abstract: Primary production must constrain the amount of fish and invertebrates available to expanding fisheries; however the degree of limitation has only been demonstrated at regional scales to date. Here we show that phytoplanktonic primary production, estimated from an ocean-colour satellite (SeaWiFS), is related to global fisheries catches at the scale of Large Marine Ecosystems, while accounting for temperature and ecological factors such as ecosystem size and type, species richness, animal body size, and the degree and nature of fisheries exploitation. Indeed we show that global fisheries catches since 1950 have been increasingly constrained by the amount of primary production. The primary production appropriated by current global fisheries is 17-112% higher than that appropriated by sustainable fisheries. Global primary production appears to be declining, in some part due to climate variability and change, with consequences for the near future fisheries catches.

375 citations


Journal ArticleDOI
02 Dec 2010-PLOS ONE
TL;DR: The growth in marine fisheries catches for more than half a century was only made possible through exploitation of new fishing grounds and their rapidly diminishing number indicates a global limit to growth and highlights the urgent need for a transition to sustainable fishing through reduction of PPR.
Abstract: Using estimates of the primary production required (PPR) to support fisheries catches (a measure of the footprint of fishing), we analyzed the geographical expansion of the global marine fisheries from 1950 to 2005. We used multiple threshold levels of PPR as percentage of local primary production to define ‘fisheries exploitation’ and applied them to the global dataset of spatially-explicit marine fisheries catches. This approach enabled us to assign exploitation status across a 0.5° latitude/longitude ocean grid system and trace the change in their status over the 56-year time period. This result highlights the global scale expansion in marine fisheries, from the coastal waters off North Atlantic and West Pacific to the waters in the Southern Hemisphere and into the high seas. The southward expansion of fisheries occurred at a rate of almost one degree latitude per year, with the greatest period of expansion occurring in the 1980s and early 1990s. By the mid 1990s, a third of the world's ocean, and two-thirds of continental shelves, were exploited at a level where PPR of fisheries exceed 10% of PP, leaving only unproductive waters of high seas, and relatively inaccessible waters in the Arctic and Antarctic as the last remaining ‘frontiers.’ The growth in marine fisheries catches for more than half a century was only made possible through exploitation of new fishing grounds. Their rapidly diminishing number indicates a global limit to growth and highlights the urgent need for a transition to sustainable fishing through reduction of PPR.

365 citations


Journal ArticleDOI
TL;DR: Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production, and the future of inland fisheries varies between continents.
Abstract: The reported annual yield from inland capture fisheries in 2008 was over 10 million tonnes, although real catches are probably considerably higher than this. Inland fisheries are extremely complex, and in many cases poorly understood. The numerous water bodies and small rivers are inhabited by a wide range of species and several types of fisher community with diversified livelihood strategies for whom inland fisheries are extremely important. Many drivers affect the fisheries, including internal fisheries management practices. There are also many drivers from outside the fishery that influence the state and functioning of the environment as well as the social and economic framework within which the fishery is pursued. The drivers affecting the various types of inland water, rivers, lakes, reservoirs and wetlands may differ, particularly with regard to ecosystem function. Many of these depend on land-use practices and demand for water which conflict with the sustainability of the fishery. Climate change is also exacerbating many of these factors. The future of inland fisheries varies between continents. In Asia and Africa the resources are very intensely exploited and there is probably little room for expansion; it is here that resources are most at risk. Inland fisheries are less heavily exploited in South and Central America, and in the North and South temperate zones inland fisheries are mostly oriented to recreation rather than food production.

340 citations


Journal ArticleDOI
18 Nov 2010-Nature
TL;DR: It is found that catch MTL does not reliably predict changes in marine ecosystems, and therefore greater efforts are recommended to measure true abundance trends for marine species, especially those most vulnerable to fishing.
Abstract: Biodiversity indicators provide a vital window on the state of the planet, guiding policy development and management. The most widely adopted marine indicator is mean trophic level (MTL) from catches, intended to detect shifts from high-trophic-level predators to low-trophic-level invertebrates and plankton-feeders. This indicator underpins reported trends in human impacts, declining when predators collapse ("fishing down marine food webs") and when low-trophic-level fisheries expand ("fishing through marine food webs"). The assumption is that catch MTL measures changes in ecosystem MTL and biodiversity. Here we combine model predictions with global assessments of MTL from catches, trawl surveys and fisheries stock assessments and find that catch MTL does not reliably predict changes in marine ecosystems. Instead, catch MTL trends often diverge from ecosystem MTL trends obtained from surveys and assessments. In contrast to previous findings of rapid declines in catch MTL, we observe recent increases in catch, survey and assessment MTL. However, catches from most trophic levels are rising, which can intensify fishery collapses even when MTL trends are stable or increasing. To detect fishing impacts on marine biodiversity, we recommend greater efforts to measure true abundance trends for marine species, especially those most vulnerable to fishing.

338 citations


Journal ArticleDOI
TL;DR: It is argued here that a “balanced exploitation” approach might alleviate many of the ecological effects of fishing by avoiding intensive removal of particular components of the ecosystem, while still supporting sustainable fisheries.
Abstract: Globally, many fish species are overexploited, and many stocks have collapsed. This crisis, along with increasing concerns over flow-on effects on ecosystems, has caused a reevaluation of traditional fisheries management practices, and a new ecosystem-based fisheries management (EBFM) paradigm has emerged. As part of this approach, selective fishing is widely encouraged in the belief that nonselective fishing has many adverse impacts. In particular, incidental bycatch is seen as wasteful and a negative feature of fishing, and methods to reduce bycatch are implemented in many fisheries. However, recent advances in fishery science and ecology suggest that a selective approach may also result in undesirable impacts both to fisheries and marine ecosystems. Selective fishing applies one or more of the "6-S" selections: species, stock, size, sex, season, and space. However, selective fishing alters biodiversity, which in turn changes ecosystem functioning and may affect fisheries production, hindering rather than helping achieve the goals of EBFM. We argue here that a "balanced exploitation" approach might alleviate many of the ecological effects of fishing by avoiding intensive removal of particular components of the ecosystem, while still supporting sustainable fisheries. This concept may require reducing exploitation rates on certain target species or groups to protect vulnerable components of the ecosystem. Benefits to society could be maintained or even increased because a greater proportion of the entire suite of harvested species is used.

330 citations


Journal ArticleDOI
TL;DR: The main changes affecting the sector are described, including geographical expansion, fishing capacity-building, natural variability, environmental degradation and climate change, which identifies drivers and future challenges, while suggesting how new science, policies and interventions could best address those challenges.
Abstract: World population is expected to grow from the present 6.8 billion people to about 9 billion by 2050. The growing need for nutritious and healthy food will increase the demand for fisheries products from marine sources, whose productivity is already highly stressed by excessive fishing pressure, growing organic pollution, toxic contamination, coastal degradation and climate change. Looking towards 2050, the question is how fisheries governance, and the national and international policy and legal frameworks within which it is nested, will ensure a sustainable harvest, maintain biodiversity and ecosystem functions, and adapt to climate change. This paper looks at global fisheries production, the state of resources, contribution to food security and governance. It describes the main changes affecting the sector, including geographical expansion, fishing capacity-building, natural variability, environmental degradation and climate change. It identifies drivers and future challenges, while suggesting how new science, policies and interventions could best address those challenges.

310 citations


Journal ArticleDOI
TL;DR: In this paper, a comprehensive database of reported data on marine turtle bycatch in gillnet, longline, and trawl fisheries worldwide from 1990 to 2008 was compiled, and the authors provided a global perspective of fisheries bycatch for marine turtles and highlighted region-gear combinations that warrant urgent conservation action.
Abstract: Fisheries bycatch is a primary driver of population declines in several species of marine megafauna (eg, elasmobranchs, mammals, seabirds, turtles) Characterizing the global bycatch seascape using data on bycatch rates across fisheries is essential for highlighting conservation priorities We compiled a comprehensive database of reported data on marine turtle bycatch in gillnet, longline, and trawl fisheries worldwide from 1990 to 2008 The total reported global marine turtle bycatch was ∼85,000 turtles, but due to the small percentage of fishing effort observed and reported (typically <1% of total fleets), and to a global lack of bycatch information from small-scale fisheries, this likely underestimates the true total by at least two orders of magnitude Our synthesis also highlights an apparently universal pattern across fishing gears and regions where high bycatch rates were associated with low observed effort, which emphasizes the need for strategic bycatch data collection and reporting This study provides the first global perspective of fisheries bycatch for marine turtles and highlights region–gear combinations that warrant urgent conservation action (eg, gillnets, longlines, and trawls in the Mediterranean Sea and eastern Pacific Ocean) and region–gear combinations in need of enhanced observation and reporting efforts (eg, eastern Indian Ocean gillnets, West African trawls)

296 citations


Journal ArticleDOI
TL;DR: In this paper, the authors discuss how fishing and climate forcing interact on individual fish, marine populations, marine communities, and ecosystems to bring these levels into states that are more sensitive to (i.e. more strongly related with) climate forcing.

287 citations


Journal ArticleDOI
TL;DR: The main finding from this review was that a combination of observational techniques, rather than a single method, was the most effective approach to marine spatial monitoring.
Abstract: Management areas are used in marine spatial planning to conserve biodiversity of marine ecosystems and to protect fish from fishing pressure. To evaluate the effectiveness of these protected areas, observational techniques are used to determine densities, sizes, biomass, habitat types and distribution of fish species in and around management areas. Two types of observational techniques are used in spatial monitoring: (1) fishery-independent techniques, which include underwater visual census (UVC), underwater video, remote sensing, acoustics, and experimental catch and effort data; and (2) fishery-dependent techniques, which include catch, effort and catch per unit effort data from commercial and recreational fisheries. This review summarises the applications, advantages, disadvantages and biases of each of these observational categories and highlights emerging technologies. The main finding from this review was that a combination of observational techniques, rather than a single method, was the most effective approach to marine spatial monitoring. For example, a combination of hydroacoustics for habitat mapping and UVC or video for fish surveys was one of the most cost-effective and efficient means of obtaining fish-habitat linkages and fish assemblage data. There are also emerging technologies that could increase the precision and efficiency of monitoring surveys. There is a need for continued development of non-intrusive technology for marine monitoring studies.

238 citations


Journal ArticleDOI
TL;DR: Statistics of annual demersal fish landings from bottom trawl catches landing in England and Wales dating back to 1889 are compiled, using previously neglected UK Government data to estimate the change in landings per unit of fishing power (LPUP), a measure of the commercial productivity of fisheries.
Abstract: Fish stocks in the ocean are known to be under threat. Here, using government data describing commercial fish landings, Thurstan and colleagues show that these stocks began to decline rapidly in the 1970s.

Journal ArticleDOI
TL;DR: In this article, an intensive pilot study was conducted to evaluate whether interview surveys can be effective in assessing fishing effort and threatened species bycatch in artisanal fisheries, and the results indicated that annual sea turtle bycatch may number at least in the low thousands of individuals per country.

Journal ArticleDOI
TL;DR: It is proposed that nomadic or home range movements of individuals near MPA boundaries, seasonal migrations and migrations forced by extraordinary meteorological events, and density-dependent movements facilitated spillover from the CIMR.
Abstract: Benefits for fisheries from marine protected areas (MPAs) are expected from recruit- ment of exported eggs and larvae as well as from spillover of adults to adjacent fishing grounds. Because the recruitment effect is difficult to detect, spillover is presently the only tangible potential fishery benefit of MPAs. Despite abundant evidence of spillover in the literature, this is the first study to quantify the number and biomass of individuals annually spilling over from an MPA and their con- tribution to the local fishery catches. Using a decade (1997-2007) of tag-recapture data for the lobster Palinurus elephas from the Columbretes Islands Marine Reserve (CIMR), we estimated annual emi- gration probabilities of 3.7% (female) and 6.7% (male), and quantified the resulting spillover to adja- cent fished areas. We showed that during an 8 to 17 yr protection period, harvested spillover offset the loss of yield resulting from the reduction of fishing grounds set aside in the CIMR, producing a mean annual net benefit of 10% of the catch in weight. Although the number of lobsters spilling over annually did not quite make up for the loss of fishing grounds in the CIMR, it did in weight because the mean size of the lobsters emigrating from the reserve was larger than that of those outside. We propose that nomadic or home range movements of individuals near MPA boundaries, seasonal migrations and migrations forced by extraordinary meteorological events, and density-dependent movements facilitated spillover from the CIMR. Fishing effort concentration along its boundaries and high exploitation rates in the local fishery limited the spatial extent of spillover.

Journal ArticleDOI
05 Aug 2010-PLOS ONE
TL;DR: Human pressures in coastal zones have lead to the broad-scale absence of sharks on reefs in the greater-Caribbean, and population viability analysis suggests that exploitation alone could explain the large- scale absence.
Abstract: Background: In recent decades, large pelagic and coastal shark populations have declined dramatically with increased fishing; however, the status of sharks in other systems such as coral reefs remains largely unassessed despite a long history of exploitation. Here we explore the contemporary distribution and sighting frequency of sharks on reefs in the greaterCaribbean and assess the possible role of human pressures on observed patterns. Methodology/Principal Findings: We analyzed 76,340 underwater surveys carried out by trained volunteer divers between 1993 and 2008. Surveys were grouped within one km 2 cells, which allowed us to determine the contemporary geographical distribution and sighting frequency of sharks. Sighting frequency was calculated as the ratio of surveys with sharks to the total number ofsurveys in each cell. We compared sighting frequency to the number of peoplein the cell vicinity and used population viability analyses to assess the effects of exploitation on population trends. Sharks, with the exception of nurse sharks occurred mainly in areas with very low human population or strong fishing regulations and marine conservation. Population viability analysis suggests that exploitation alone could explain the large-scale absence; however, this pattern is likely to be exacerbated by additional anthropogenic stressors, such as pollution and habitat degradation, that also correlate with human population. Conclusions/Significance: Human pressures in coastal zones have lead to the broad-scale absence of sharks on reefs in the greater-Caribbean. Preventing further loss of sharks requires urgent management measures to curb fishing mortality and to mitigate other anthropogenic stressors to protect sites where sharks still exist. The fact that sharks still occur in some densely populated areas where strong fishing regulations are in place indicates the possibility of success and encourages the implementation of conservation measures.

Journal ArticleDOI
TL;DR: Recreational fisheries and nature conservation goals for aquatic biodiversity with specific reference to inland waters in industrialized countries are reviewed, and the principal management activities and constraints that can lead to conflicts are reviewed.
Abstract: The importance of recreational fisheries to local and national economies, and as a generator of immense social welfare throughout the developed world, is well established. Development in the sector and its interaction with non-fishery-related nature conservation objectives for aquatic biodiversity, however, have the potential to generate conflict. This article reviews the intersection between recreational fisheries and nature conservation goals for aquatic biodiversity with specific reference to inland waters in industrialized countries, and the principal management activities and constraints that can lead to conflicts. A SWOT (strengths, weaknesses, opportunities and threats) analysis was used to review the issues facing sectoral development and identify options for future advancement of recreational fisheries to ameliorate potential conflicts with nature conservation goals. It is concluded that reconciliation of recreational fisheries and modern conservation perspectives is both possible and desirable, because many conservation problems also benefit fisheries quality. Angler buy-in to conservation is probable if (1) management scales are small, (2) threats to conservation originate from outside the fisheries sectors and (3) ecological awareness for the conservation problem is high. If these aspects are not present, reconciliation of recreational fisheries and nature conservation goals is less likely, risking both the aquatic biodiversity and the future of angling. To address these issues, enforcement of legislation and continued communication with angler communities is necessary, as well as development of integrated management policies that build on the instrumental values of aquatic biodiversity for recreational fisheries, while curtailing the more insidious threats to such biodiversity that originate directly from the recreational fisheries sector.

Journal ArticleDOI
TL;DR: A widespread phenomenon of age (size)-truncation of exploited populations driven by size-selective fishery removals is documented.
Abstract: Overfishing has caused dramatic changes in structures of exploited populations as well as ecosystems. In this article, we focus on fishing effects on age (size) and spatial structures of exploited fishes. Accumulating evidence has shown that large and experienced spawning individuals are able to produce higher quality and quantity of eggs, known as maternal effects, and that individuals of different age classes tend to spawn in different locations and times. These behaviors are associated with a healthy age structure and contribute to bet-hedging capacity that is important in smoothing out short-term environmental variability. Here, we document a widespread phenomenon of age (size)-truncation of exploited populations driven by size-selective fishery removals. Such size-selective fishing may have evolutionary consequence and may be difficult to reverse. In addition, fishing often reduces population spatial heterogeneity that also contributes importantly to bet-hedging. We review studies showing that the effects of age truncation and reduction of spatial heterogeneity have reduced resilience and elevated the fluctuation amplitude of exploited populations facing a changing environment. Recent analyses indicated that fish populations often exhibit nonlinear nature and have potential to shift dramatically in a short time. All the evidence suggests that fishing, by altering age or spatial structures, may make exploited fishes, more prone to catastrophic shifts. Therefore, to achieve sustainable fisheries, management should conserve the age and spatial structure in addition to viable spawning biomass.

Journal ArticleDOI
TL;DR: In this paper, the authors describe the potential catch losses due to unsustainable fishing in all countries' exclusive economic zones (EEZs) and on the high seas over 1950-2004.
Abstract: Excess fishing capacity and the growth in global demand for fishery products have made overfishing ubiquitous in the world’s oceans. Here we describe the potential catch losses due to unsustainable fishing in all countries’ exclusive economic zones (EEZs) and on the high seas over 1950–2004. To do so, we relied upon catch and price statistics from the Sea Around Us Project as well as an empirical relationship we derived from species stock assessments by the U.S. National Oceanic and Atmospheric Administration. In 2000 alone, estimated global catch losses amounted to 7–36% of the actual tonnage landed that year, resulting in a landed value loss of between $6.4 and 36 billion (in 2004 constant US$). From 1950–2004, 36–53% of commercial species in 55–66% of EEZs may have been overfished. Referring to a species-level database of intrinsic vulnerability (V) based on life-history traits, it appears that susceptible species were depleted quickly and serially, with the average V of potential catch losses declining at a similar rate to that of actual landings. The three continental regions to incur greatest losses by mass were Europe, North America, and Asia—forming a geographic progression in time. But low-income and small island nations, heavily dependent on marine resources for protein, were impacted most profoundly. Our analysis shows that without the inexorable march of overfishing, ~20 million people worldwide could have averted undernourishment in 2000. For the same year, total catch in the waters of low-income food deficit nations might have been up to 17% greater than the tonnage actually landed there. The situation may be worst for Africa, which in our analysis registered losses of about 9–49% of its actual catches by mass in year 2000, thus seriously threatening progress towards the UN Millennium Development Goals.

Journal ArticleDOI
TL;DR: Investigation of long-term variability within a demersal fish assemblage in the western English Channel showed that temporal trends in the abundance of smaller multispecies size classes followed thermal regime changes, but that there were persistent declines in abundance of larger size classes.
Abstract: Commercial fishing and climate change have influenced the composition of marine fish assemblages worldwide, but we require a better understanding of their relative influence on long-term changes in species abundance and body-size distributions. In this study, we investigated long-term (1911‐2007) variability within a demersal fish assemblage in the western English Channel. The region has been subject to commercial fisheries throughout most of the past century, and has undergone interannual changes in sea temperature of over 2.01C. We focussed on a core 30 species that comprised 99% of total individuals sampled in the assemblage. Analyses showed that temporal trends in the abundance of smaller multispecies size classes followed thermal regime changes, but that there were persistent declines in abundance of larger size classes. Consistent with these results, larger-growing individual species had the greatest declines in body size, and the most constant declines in abundance, while abundance changes of smaller-growing species were more closely linked to preceding sea temperatures. Together these analyses are suggestive of dichotomous size-dependent responses of species to long-term climate change and commercial fishing over a century scale. Small species had rapid responses to the prevailing thermal environment, suggesting their life history traits predisposed populations to respond quickly to changing climates. Larger species declined in abundance and size, reflecting expectations from sustained size-selective overharvesting. These results demonstrate the importance of considering species traits when developing indicators of human and climatic impacts on marine fauna.

Journal ArticleDOI
TL;DR: Consolidating post-1950 global catch and economic data, which attributes of fisheries are good indicators for fishery development and economic value highlights the importance of economic attributes of species as leading indicators for harvest-related impacts in ocean ecosystems.
Abstract: Successful ocean management needs to consider not only fishing impacts but drivers of harvest. Consolidating post-1950 global catch and economic data, we assess which attributes of fisheries are good indicators for fishery development. Surprisingly, year of development and economic value are not correlated with fishery trophic levels. Instead, patterns emerge of profit-driven fishing for attributes related to costs and revenues. Post-1950 fisheries initially developed on shallow ranging species with large catch, high price, and big body size, and then expanded to less desirable species. Revenues expected from developed fisheries declined 95% from 1951 to 1999, and few high catch or valuable fishing opportunities remain. These results highlight the importance of economic attributes of species as leading indicators for harvest-related impacts in ocean ecosystems.

Journal ArticleDOI
TL;DR: In this paper, the authors applied an input-output methodology to estimate the total direct, indirect, and induced impact of marine capture fisheries on the world economy, and found that significant indirect and induced effects place the impact of this sector to world output nearly three times larger than the value of landings at first sale, at between US $225 and 240 billion per year.
Abstract: Our goal in this paper is to estimate the total output in an economy that is currently dependent (at least partially) on current fisheries output. We therefore applied the Leontief technological coefficients at current production and then estimate total output supported throughout the economy at the current level of production. Estimates of gross revenue from capture fisheries suggest that the direct value of output for this sector is US $80–85 billion annually (Sumaila et al., Journal of Bioeconomics 9(1):39–51, 2007; Willmann et al., The Sunken Billions, World Bank, FAO, Washington DC, Rome, 2009). However, as a primary or a potential economic base industry, there are a vast number of secondary economic activities—from boat building to international transport—that are supported by world fisheries, yet these related activities are rarely considered when evaluating the economic impact of fisheries. This study applies an input–output methodology to estimate the total direct, indirect, and induced impact of marine capture fisheries on the world economy. While results suggest that there is a great deal of variation in fishing output multipliers between regions and countries, when we apply the output multipliers to the capture fisheries sector at the global level, we find that significant indirect and induced effects place the impact of this sector to world output nearly three times larger than the value of landings at first sale, at between US $225 and 240 billion per year.

Journal ArticleDOI
TL;DR: A deep history of anthropogenic effects on the marine ecosystems of California's Channel Islands through the past 12,000 years and geographic variation in the effects of human fishing on Pacific Island peoples who spread through Oceania during the late Holocene are examined.
Abstract: Interdisciplinary study of coastal archaeological sites provides a wealth of information on the ecology and evolution of ancient marine animal populations, the structure of past marine ecosystems, and the history of human impacts on coastal fisheries. In this paper, we review recent methodological developments in the archaeology and historical ecology of coastal regions around the world. Using two case studies, we examine (a) a deep history of anthropogenic effects on the marine ecosystems of California's Channel Islands through the past 12,000 years and (b) geographic variation in the effects of human fishing on Pacific Island peoples who spread through Oceania during the late Holocene. These case studies—the first focused on hunter-gatherers, the second on maritime horticulturalists—provide evidence for shifting baselines and timelines, documenting a much deeper anthropogenic influence on many coastal ecosystems and fisheries than considered by most ecologists, conservation biologists, and fisheries man...

Journal ArticleDOI
TL;DR: In this article, the authors review how these fisheries grew from 1995 to 2005, and provide insights into the relative importance of different fishing gears and their modes of operation, and highlight the need for increased research and management measures to ensure the long term viability of these fisheries.

Journal ArticleDOI
TL;DR: Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish < 20 cm, which will compound effects of fishing on coral reefs.
Abstract: Overfishing and habitat degradation through climate change pose the greatest threats to sustainability of marine resources on coral reefs. We examined how changes in fishing pressure and benthic habitat composition influenced the size spectra of island-scale reef fish communities in Lau, Fiji. Between 2000 and 2006 fishing pressure declined in the Lau Islands due to declining human populations and reduced demand for fresh fish. At the same time, coral cover declined and fine-scale architectural complexity eroded due to coral bleaching and outbreaks of crown-of-thorns starfish, Acanthaster planci. We examined the size distribution of reef fish communities using size spectra analysis, the linearized relationship between abundance and body size class. Spatial variation in fishing pressure accounted for 31% of the variation in the slope of the size spectra in 2000, higher fishing pressure being associated with a steeper slope, which is indicative of fewer large-bodied fish and/or more small-bodied fish. Conversely, in 2006 spatial variation in habitat explained 53% of the variation in the size spectra slopes, and the relationship with fishing pressure was much weaker (;12% of variation) than in 2000. Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish ,20 cm. Habitat degradation will compound effects of fishing on coral reefs as increased fishing reduces large-bodied target species, while habitat loss results in fewer small-bodied juveniles and prey that replenish stocks and provide dietary resources for predatory target species. Effective management of reef resources therefore depends on both reducing fishing pressure and maintaining processes that encourage rapid recovery of coral habitat.

Journal ArticleDOI
TL;DR: In South Africa, foraging effort of breeding African penguins decreased by 30 per cent within three months of closing a 20 km zone to the competing purse-seine fisheries around their largest colony, demonstrating the immediate benefit of a relatively small no-take zone for a marine top predator relying on pelagic prey.
Abstract: No-take zones may protect populations of targeted marine species and restore the integrity of marine ecosystems, but it is unclear whether they benefit top predators that rely on mobile pelagic fishes. In South Africa, foraging effort of breeding African penguins decreased by 30 per cent within three months of closing a 20 km zone to the competing purse-seine fisheries around their largest colony. After the fishing ban, most of the penguins from this island had shifted their feeding effort inside the closed area. Birds breeding at another colony situated 50 km away, whose fishing grounds remained open to fishing, increased their foraging effort during the same period. This demonstrates the immediate benefit of a relatively small no-take zone for a marine top predator relying on pelagic prey. Selecting such small protected areas may be an important first conservation step, minimizing stakeholder conflicts and easing compliance, while ensuring benefit for the ecosystems within these habitats.

Journal ArticleDOI
29 Dec 2010-PLOS ONE
TL;DR: It is suggested that estimates of fishing effort, not just target catch or yield, serve as a necessary measure of fishing activity, which is a key link to evaluating sustainability and environmental impacts of coastal fisheries.
Abstract: Biodiverse coastal zones are often areas of intense fishing pressure due to the high relative density of fishing capacity in these nearshore regions. Although overcapacity is one of the central challenges to fisheries sustainability in coastal zones, accurate estimates of fishing pressure in coastal zones are limited, hampering the assessment of the direct and collateral impacts (e.g., habitat degradation, bycatch) of fishing. We compiled a comprehensive database of fishing effort metrics and the corresponding spatial limits of fisheries and used a spatial analysis program (FEET) to map fishing effort density (measured as boat-meters per km2) in the coastal zones of six ocean regions. We also considered the utility of a number of socioeconomic variables as indicators of fishing pressure at the national level; fishing density increased as a function of population size and decreased as a function of coastline length. Our mapping exercise points to intra and interregional ‘hotspots’ of coastal fishing pressure. The significant and intuitive relationships we found between fishing density and population size and coastline length may help with coarse regional characterizations of fishing pressure. However, spatially-delimited fishing effort data are needed to accurately map fishing hotspots, i.e., areas of intense fishing activity. We suggest that estimates of fishing effort, not just target catch or yield, serve as a necessary measure of fishing activity, which is a key link to evaluating sustainability and environmental impacts of coastal fisheries.

Journal ArticleDOI
01 Jan 2010-Oryx
TL;DR: In this paper, the authors review difficulties that may impede further progress, such as consumer confusion, lack of traceability and a lack of demonstrably improved conservation status for the fish that are meant to be protected.
Abstract: Over the past decade conservation groups have put considerable effort into educating consumers and changing patterns of household consumption. Many groups aiming to reduce overfishing and encourage sustainable fishing practices have turned to new market-based tools, including consumer awareness campaigns and seafood certification schemes (e.g. the Marine Stewardship Council) that have been well received by the fishing and fish marketing industries and by the public in many western countries. Here, we review difficulties that may impede further progress, such as consumer confusion, lack of traceability and a lack of demonstrably improved conservation status for the fish that are meant to be protected. Despite these issues, market-based initiatives may have a place in fisheries conservation in raising awareness among consumers and in encouraging suppliers to adopt better practices. We also present several additional avenues for market-based conservation measures that may strengthen or complement current initiatives, such as working higher in the demand chain, connecting seafood security to climate change via life cycle analysis, diverting small fish away from the fishmeal industry into human food markets, and the elimination of fisheries subsidies. Finally, as was done with greenhouse gas emissions, scientists, conservation groups and governments should set seafood consumption targets.

Journal ArticleDOI
TL;DR: In this paper, the effects of individual quotas on spatial and temporal effort allocation and over-quota discarding in a multispecies fishery were analyzed using a spatially explicit dynamic-state variable model.
Abstract: Many fisheries are managed by total allowable catches (TACs) and a substantial part by individual quotas. Such output management has not been successful in mixed fisheries when fishers continue to fish while discarding marketable fish. We analyse the effects of individual quotas on spatial and temporal effort allocation and over-quota discarding in a multispecies fishery. Using a spatially explicit dynamic-state variable model, the optimal fishing strategy of fishers constrained by annual individual quotas, facing uncertainty in catch rates, is studied. Individual fishers will move away from areas with high catches of the restricted quota species and, depending on the cost of fishing, will stop fishing in certain periods of the year. Individual vessels will discard marketable fish, but only after their individual quota for the species under consideration has been reached. These results are in line with observations on effort allocation and discarding of marketable fish, both over-quota discarding and highgrading, by the Dutch beam-trawl fleet. The models we present can be used to predict the outcomes of management and are therefore a useful tool for fisheries scientists and managers.

Journal ArticleDOI
TL;DR: In this article, the authors review assessments of turtle interactions in these fisheries, and experiments on gear-technology approaches (modifying gear designs, materials and fishing methods) to mitigate turtle by-catch, available from a small number of studies and fisheries.
Abstract: There is growing evidence that small-scale, coastal, passive net fisheries may be the largest single threat to some sea turtle populations. We review assessments of turtle interactions in these fisheries, and experiments on gear-technology approaches (modifying gear designs, materials and fishing methods) to mitigate turtle by-catch, available from a small number of studies and fisheries. Additional assessments are needed to improve the limited understanding of the relative degree of risk coastal net fisheries pose to turtle populations, to prioritize limited conservation resources and identify suitable mitigation opportunities. Whether gear technology provides effective and commercially viable solutions, alone or in combination with other approaches, is not well-understood. Fishery-specific assessments and trials are needed, as differences between fisheries, including in gear designs; turtle and target species, sizes and abundance; socioeconomiccontext; andpracticality affectefficacyandsuitabilityofbycatch mitigation methods. Promising gear-technology approaches for gillnets and trammelnetsinclude:increasinggearvisibilitytoturtlesbutnottargetspecies,through illuminationandlinematerials;reducingnetverticalheight;increasingtiedownlength or eliminating tiedowns; incorporating shark-shaped silhouettes; and modifying float characteristics, the number of floats or eliminating floats. Promising gear-technology approachesforpoundnetsandothertrapgearinclude:replacingmeshwithropesinthe upperportionofleaders;incorporatingaturtlereleasingdeviceintotraps;modifyingthe shape of the trap roof to direct turtles towards the location of an escapement device; usinganopentrap;andincorporatingadevicetopreventseaturtleentranceintotraps.

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TL;DR: In this paper, the authors analyse stock assessment data of all major fish stocks of the Northeast Atlantic to determine whether Europe will be able to deliver on this commitment, which it has helped to bring about.
Abstract: Maintaining or restoring fish stocks at levels that are capable of producing maximum sustainable yield is a legal obligation under the United Nations Convention on the Law of the Sea (UNCLOS) and has been given the deadline of no later than 2015 in the Johannesburg Plan of Implementation of 2002. Here, we analyse stock assessment data of all major fish stocks of the Northeast Atlantic to determine whether Europe will be able to deliver on this commitment, which it has helped to bring about. The analysis shows that, if current fishing pressure continues, 91% of the European stocks will remain below target. If European ministers in charge of fisheries were serious about meeting their obligations, they would have to reduce drastically fishing pressure and halt fishing completely on some stocks. But even if fishing were halted in 2010, 22% of the stocks are so depleted that they cannot be rebuilt by 2015. If current trends continue, Europe will miss the 2015 deadline by more than 30 years. We argue that, from a legal perspective, such repeated enactment of fisheries management measures,which are incapable of maintaining or restoring Bmsy, does not comply with the requirements contained in UNCLOS and may constitute a breach of the precautionary principle of European Community law.

Journal Article
TL;DR: The most comprehensive and interdisciplinary work on marine conservation and fisheries management ever compiled as mentioned in this paper is the first to bridge fisheries and marine conservation issues, which provides a global special perspective over time and treat problems in the high seas, community fisheries, industrial fishing, and the many interactions between use and non-use of the oceans.
Abstract: This handbook is the most comprehensive and interdisciplinary work on marine conservation and fisheries management ever compiled. It is the first to bridge fisheries and marine conservation issues. Its innovative ideas, detailed case studies, and governance framework provide a global special perspective over time and treat problems in the high seas, community fisheries, industrial fishing, and the many interactions between use and non-use of the oceans. Its policy tools and ideas for overcoming the perennial problems of over fishing, habitat and biodiversity loss address the facts that many marine ecosystems are in decline and plagued by overexploitation due to unsustainable fishing practices. An outstanding feature of the book is the detailed case-studies on conservation practice and fisheries management from around the world. These case studies are combined with 'foundation' chapters that provide an overview of the state of the marine world and innovative and far reaching perspectives about how we can move forward to face present and future challenges. The contributors include the world's leading fisheries scientists, economists, and mangers. Ecosystem and incentive-based approaches are described and complemented by tools for cooperative, participatory solutions. Unique themes treated: fisher behavior and incentives for management beyond rights-based approaches; a synthesis of proposed 'solutions'; a framework for understanding and overcoming the critical determinants of the decline in fisheries, degradation of marine ecosystems, and poor socio-economic performance of many fishing communities; models for innovative policy instruments; a plan of action and adoption pathways to promote sustainable fishing practices globally. Collectively, the handbook's many valuable contributions offer a way forward to both understanding and resolving the multifaceted problems facing the world's oceans.